Multilayer Switch Started Guide Catalyst 3550

11
Warning Installation of the equipment must comply with local and national electrical codes.
Statement 1074
Warning Statements for Connecting to DC Power
These statements apply when connecting a Catalyst 3550-24-DC switch to DC power.
Warning When installing the unit, always make the ground connectionfirstand disconnectit last.
Statement 42
Warning An exposed wire lead from a DC-input power source can conduct harmful levels of
electricity. Be sure that no exposed portion of the DC-input power source wire extends
from the terminal block plug. Statement 122
Warning Before connecting or disconnecting ground or power wires to the chassis, ensure that
power is removed from the DC circuit. To ensure that all power is OFF, locate the circuit
breaker on thepanel board that servicesthe DC circuit, switch the circuit breaker to the
OFF position, and tape the switch handle of the circuit breaker in the OFF position.
Statement 140
Caution To make sure that the equipment is reliably connected to earth ground, follow the
grounding procedure instructions, and use a UL-listed lug suitable for number-6 AWG
wire and two number-10-32 ground-lug screws.
Caution You must connect the Catalyst 3550-24-DC switch only to a DC-input power source that
has an input supply voltage from –36 to –72 VDC. If the supply voltage is not in this
range, the switch might not operate properly or might be damaged.
Caution The switch must be installed with 5-A branch-circuit protection.